With the development of the display technique, the requirements for the quality of displaying image from the user are higher and higher. Human beings can obtain a better visual experience from the vivid colors, and thus at present more and more driving chips for liquid crystal displays incorporate a function of image color enhancement.
Currently, the general methods for image color enhancement can be divided into two classes, wherein in a first group of methods for image color enhancement, same scales and shifts are made on the primary color components, i.e., Red color, Green color and Blue Color, without space conversion, so as to achieve the purpose of keeping the tone unchanged; in a second group of methods for image color enhancement, the color components are converted from RGB space to other spaces, a corresponding operation processing is performed, and then the color components are converted back into the RGB space. Compared to the first group of methods for image color enhancement, the second group of methods for image color enhancement is better, since it can achieve the enhancement on the image colors. The purpose of enhancing image color is to improve the display quality of image; however, after the space conversion, if the gains in the operation are improper, that is, the gain operation is made on all the components without judgment, the following problems might occur after the image color enhancement: in a case of grey level in solid color, the color as displayed can vary due to the gain operation on the saturation value, resulting in color bias in the grey level in solid color; in a case of a color picture, the phenomenon of over-saturation can occur when the picture such as a skin color is display due to the gain operation on the saturation value.
Therefore, if no analysis and judgment is made on the parameters of each component in the converted space after the space conversion, it is impossible to perform a proper gain operation, and in turn a scheme for the gain operation can not be selected, further resulting in color bias and over-saturation, thus resulting in deteriorating the image quality.